perf(source-map): avoid quadratic indented-code suffix search - #118
Merged
Merged
Conversation
Calculate the suffix start once. Scan the whitespace prefix and value once. Add a fallback benchmark with an input growth check. Closes #117.
Document the literal-suffix invariant. Give the benchmark fixture a precise name.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Performance
Batch measurements compared this branch with its parent commit.
Large-prefix latency falls by approximately 35% to 40%.
The smoke benchmark measured 4.06x time growth for a 4x input increase.
This result matches linear growth.
The old algorithm has a potential O(n²) cost when string slices require copying.
The new algorithm has O(n) cost and does not create temporary suffix strings.
Current V8 versions optimize string slices, so their measured speedup is smaller.
Tests
pnpm testpnpm run buildnode scripts/bench-source-map.mjs --smokeCloses #117.